walker



(No Model.) 2 Sheets-Sheet 1.' J. L. 8: G. B. WALKER. ELEGTRIG FIREALARMSYSTEM.

No. 590,603. Patented Sept. 28, 1897.

WITNESSES (1%, @M/Jl (No Model.) 2 Sheets-Shet 2.

J. L. & G. B. WALKER. ELECTRIC FIRE ALARM SYSTEM.

No. 590,603. Patented Sept. 28,1897.

a; 7 v J 7 f3 5 WITNESS m: Noam: PmRS co PHD'QLITHKL WASHINGTON, n. c.

NITED STATES- P TENT Enron.

JOHN LAURENCE WALKER AND GEORGE BROSENHAM 'IVALKER, OF

PENSACOLA, FLORIDA.

ELECTRIC FIRE-ALARM SYSTEM. A

SPECIFICATION forming part of Letters Patent No. 590,603, datedSeptember 28, 1897.

Application filed January 12 1897. Serial No; 615,988. (No model.) I

KER and GEORGE BROSENHAM WALKER, citi I zens of the United States,residing at Pensacola, in the county of Escambia and State of Florida,have invented certain new and useful Improvements in Electric Fire-AlarmSystems, of which the following is a full and complete specification,such as will enable those skilled in the art to which it appertains tomake and use the same.

This invention relates to telephones for use on any closed electriccircuit either separate from or in combination with an electricfirealarm or telegraph signal system or any telegraph or telephonesystem or systems using a. continuous electric current or a closedelectric circuit; and the object of the invention is to provide animproved portable or stationary telephone and suitable applianceswhereby a person having accessto any wire over which a continuouselectric current passes and provided with suitable appliances may sendin a call, signal, or alarm or communicate with a person at the centralor main station or with any person provided with like appliances at apoint or anynumber of points along said line or circuit or lines or"circuits connected therewith.

The invention is fully disclosed in the following specification, ofwhich the accompanying drawings form a part, in which Figure l is adiagrammatic view of a firealarm station, showing also the main circuitconnected therewith and showing also our improvement; Fig. 2, a View ofarplug which forms a part of the apparatus of the main station; Fig. 3,a plan view of a'spring-contact device which also forms a part of theappa- 'atus at the main station 5 Fig. 4, a front view thereof; Fig. 5,a sectional view of the telephone which we employ, showingthe partsdisconnected; and Fig. 6a transverse section of a signal-box, anydesired number of which may be employed along the line of the mainfire-alarm system.

In the drawings forming part of this specification the separate parts ofour improvement are designated by the same letters of referencethroughout the several views, and

in the practice of our invention we provide a telephone and telephonesignal apparatus which is adapted to be used in connection with the'main'battery and circuit of any electric fire alarm system'for bothsignaling and talking purposes.

The transmitter used in our telephone is of the granular carbon form andthe receiver of the watchcase pattern and of the single-pole type, whichwhen used in connection with any firealarm system will not interferewith i the registering of the indicator ifan alarm should be turned infrom any point while the apparatus which we employ along the maincircuit is in use.

InFig. 1 we have shown at A any suitable battery for operating anelectric fire-alarm system, also the usual indicator a, these partsbeing similar to those used in all electric firealarm systems; and wehave also shownin said figure a number of poles a on one of which is oneof our signal-boxes D, and the battery, the indicator A, and the box D,any desired number of which may be employed throughout the circuit ofthe alarm system, are placed in electrical connection by a main wire orconductor 01 and a return wire or conductor 6?, by which a completecircuit is formed.

Arranged adjacent to the indicator a Within the station are twocontact-springs F, which are secured to the walls of the station by a-The telephone B is shown in sectional de-- tail in Fig. 5 and consistsof a tubular casing b, with which the transmitter b is connected at oneend, and the opposite endof which is open and adapted to receive thereceiver 12 The receiverb while being detachable from the casing b ofthe transmitter is connected with said transmitter by the usual wires orconductors b, and. said casing 1) being provided with a diaphragm orpartition-plate 11 through which pass screws or bolts b", with which thewires or conductors Zr connect, and corresponding wires or conductors bconnect with the screws or bolts 1)" and with the separate parts of thetransmitter in the usual manner, and connected with one of the wires orconductors I) are two wires 11 which pass through the side of the casingZ) and are connected with a circuit making and breaking plug 0.

The boxes D, any desired number of which may be employed, are alsoprovided with contact-springs F, similar to those hereinbeforedescribed, which are also connected with a plate f and which are alsobrought together at the middle, as shown at f, and separated at theirouter ends, as shown at J, and the main wire or conductor cl isconnected with said contact-sprin gs bybranches d this connection beingmade in the same manner as the similar connection at the station. One ofthe telephones B is also employed in each of the boxes D and is adaptedto be suspended from the side thereof, as shown in Figs. 6 and 7, andthe telephone B in the box or boxes D is provided with a circuit makingand breaking plug K.

The telephone B in the boxes D and the telephone B at the main stationare of the same construction, but the plug K, which is connected withthe telephone in the box D, differs in construction from the plug C,which is connected with the telephone at the main station.

The plug C is designed to make or close the circuit through thetelephone without breakin g the main circuit, whereby the adjacentindicator will not be affected, while the plug K is designed to breakthe circuit before closing it, so that the indicator at the station willbe operated when the box-telephone is used.

The plug K is provided with a handle 7d, through which the wires 11pass, and the plug K consists of a central core having a wedge-shapedhead of non-conducting material, while the body portion of the plug isprovided with metal-end side plates 70, with which the wires Z1 connect,as clearly shown in Fig. 5, and the plug 0, which is adapted to closethe circuit through the telephone without breaking the circuit to theindicator, is composed of a handle 0 to which the plug proper issecured, saidplug consisting of a central portion 0*, which iswedge-shaped in form at its outer end and which is provided with metalside strips or plates 0 and passing through the handle and connectingwith said side strips or plates (1' are two wires G which connect withthe telephone or with the receiver and the transmitter thereof, ashereinbefore described with reference to the plug K. It will beunderstood that by in serting the plug K between the springs F in thebox D the circuit will be completed through the telephone and throughthe main circuit of the signal system, and when this plug is firstinserted the circuit, of which the springs F in the box Dform a part,will be broken by the separation of said springs and the alarm connectedwith the indicator to will be operated, this operation being accomplished by the wedge-shaped head 70 of the plug K; but when said headpasses between the central portions of said spring in the box D thecircuit will be again completed and any desired communication may beheld between the policeman or the party at the box D and those in chargeof the main station.

In order for the person in charge of the main station to communicatewith the policeman at the box D, the plug 0 must be inserted between thesprings at the station, and it will also be understood that when theplugs O and K are connected, as described, with the springs F at the boxD and at the station the telephones B at the box and at the station maybe used in the usual manner without interfering with the main circuit orthe signal system.

\Vith the improved telephone and other appliances herein described itwill be apparent that a person or persons provided therewith and havingaccess to the main wires or conductors of an electric-signal system,firealarm system, telephone or telegraphic system may send in a call,signal, or alarm, or communicate with a person at the central or mainstation or with any person provided with a like telephone and appliancesat any point or points throughout the system, and it will thus be seenthat we accomplish the object of our invention by means of an apparatuswhich is simple in construction and operation and which is alsocomparatively inexpensive, and it will be understood that any desirednumber of the poles a and of the boxes D may be employed, said boxes Dbe ing located wherever desired throughout the circuit of the signalsystem.

Having fully described our invention, we claim as new and desire tosecure by Letters Patent- In a continuous-circuit system the combinationof the main station and sub or signal stations, of an alarm at the mainstation located in the continuous circuit, a telephone at the mainstation having means for bringing it into the continuous circuit withouta break therein, a telephone located at the substation normally out ofthe continuous circuit and means for bringing it into the con tinuouscircuit and at the same time signaling lot at the main station,consisting of a pair of spring-arms in contact with each other andlocated in the continuous circuit, and a plug connected with thetelephone formed with a wedge-shaped non-conduetin g head which isadapted to part the springs to break the cirpresence of the subscribingWitnesses, this cuit and thereby signal at the main station, 21st day ofDecember, 1896. and With a metal contactpoint for, again V T closing thecircuit and bringing the telephone into the continuous circuit,substantially as 1 l shown and described. Witnesses:

In testimony that We claim the foregoing as 7 'JOHN EAGAN, our inventionWe have signed our names, in V DENNIS EAGAN Jr.

